Pectoralis major origin and insertion

Pectoralis major runs from the clavicle, manubrium, body of sternum and second to sixth costal cartilages to the humerus. It has three parts: the clavicular part, the sternocostal part and the abdominal part.

What are the origin and insertion of pectoralis major?

Pectoralis major arises from the medial half of the clavicle, the front of the manubrium, the front of the body of the sternum, the costal cartilages of the upper ribs and the aponeurosis of the external oblique. It inserts on the crest of the greater tubercle, the lateral lip of the intertubercular groove. Its main actions are shoulder adduction and medial rotation at the shoulder. It is supplied by the lateral and medial pectoral nerves (C5, C6, C7, C8, T1). The attachments, actions and nerve follow Gray (1918).

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Every attachment and its bone

Origins 5

Origins of pectoralis major, with the bone each is on
Attachment	Bone	Part
Medial half of the clavicle	Clavicle	Clavicular part
Front of the manubrium	Manubrium	Sternocostal part
Front of the body of the sternum	Body of sternum	Sternocostal part
Costal cartilages of the upper ribs	Second to sixth costal cartilages	Sternocostal part
Aponeurosis of the external oblique	None The external oblique’s aponeurosis is not segmented as its own structure, so this attachment cannot be painted.	Abdominal part

Insertion 1

Insertion of pectoralis major, with the bone each is on
Attachment	Bone	Part
Crest of the greater tubercle, the lateral lip of the intertubercular groove	Humerus	All parts

Actions

The actions of pectoralis major, and which are its main ones
Action	What moves	Main or assisting
Shoulder adduction	The arm comes down to the side	Main action
Medial rotation	With the elbow bent, the forearm swings in	Main action
Shoulder flexion, clavicular part	The arm swings forward	Assists
Shoulder extension, sternocostal part, from flexion	The arm swings back	Assists

Each action is stated in the anatomical position: standing, arms by the sides, palms forward.

Innervation

The lateral and medial pectoral nerves (C5, C6, C7, C8, T1).

Lifts that use pectoralis major

A prime mover produces the lift’s main joint action against the load; a synergist assists that action, or adds a secondary action the lift needs. Each role is the one the lift’s own page gives, for the technique that page states.

Prime mover in 7

Lifts in which pectoralis major is a prime mover, with what it does there
Lift	Part	What it does there
Flat bench press	Pectoralis major, clavicular part	Bringing the upper arm across and up
Flat bench press	Pectoralis major, sternal part	Bringing the upper arm across the chest
Incline bench press	Pectoralis major, clavicular part	Raising the upper arm forward and across The incline shifts work towards the clavicular part (Lauver et al. 2016).
Push-up	Pectoralis major, clavicular part	Pushing the chest away from the hands
Push-up	Pectoralis major, sternal part	Pushing the chest away from the hands
Parallel-bar dip	Pectoralis major, sternal part	Drawing the upper arm forward and down
Standing overhead press	Pectoralis major, clavicular part	Shoulder flexion through the first part of the press

Synergist in 5

Lifts in which pectoralis major is a synergist, with what it does there
Lift	Part	What it does there
Incline bench press	Pectoralis major, sternal part	Bringing the upper arm across the chest Less active than in the flat press (Barnett et al. 1995).
Parallel-bar dip	Pectoralis major, clavicular part	Shoulder flexion
Pull-up	Pectoralis major, sternal part	Pulling the upper arm down from overhead
Chin-up	Pectoralis major, sternal part	Pulling the upper arm down from overhead More active in the chin-up than the pull-up (Youdas et al. 2010).
Lat pulldown	Pectoralis major, sternal part	Pulling the upper arm down from overhead

Its parts are also stabilizers in the front plank (pectoralis major, sternal part).

Sources

Gray (1918), Myology, the muscles connecting the upper extremity to the anterior and lateral thoracic walls

Each lift role is from that lift’s page in muscles worked by exercise, which names the sources it follows.

See it in 3D

Visualiser · Biology Muscle Origin, Insertion and Action Explorer Paint a muscle’s origin and insertion on real 3D bones, or click a bone to see what attaches to it. Visualiser · Biology Upper Limb Muscles Explorer 114 upper limb muscle meshes, by compartment. Visualiser · Biology Muscles Worked by Exercise 3D Explorer Choose a lift and a real body lights its prime movers, synergists and stabilisers, front and back, with the same muscles in 3D.